Question

我是C＃的新手。请帮帮我。

 class BasicPay
    {
        public int employee_personal_id { get; set; }
        public int grade_id { get; set; }
        public int position_id { get; set; }
        public Int32 base_pay { get; set; }
        public Int32 housing { get; set; }

    private static void getEmployeeForEmpFinance(int empPersionalinfoID)
        {

            var context = new SSPModel.sspEntities();
            var query = from c in context.Employee_Financial
                        join d in context.Employee_Employ on
                        c.Employee_Personal_InfoEmp_id equals d.Employee_Personal_InfoEmp_id
                        where c.Employee_Personal_InfoEmp_id == empPersionalinfoID
                        select new { c.ID, c.Employee_Personal_InfoEmp_id, c.Base_Pay, c.Housing_Allowance, d.Grade_Id };
            var y = query.SingleOrDefault();
            var basic = new List<BasicPay>();

           **basic.Add(y.Employee_Personal_InfoEmp_id,y.Grade_Id);** // THIS IS WHAT I DO NOT UNDERSTAND

        }

}

注释行是我没有得到的。我是由自己的BasicPay类创建的。现在我如何将结果添加到此？请帮帮我。我迫切需要！

EDITED ----- 所以我使用了下面一个人的建议并且它工作了，我试图改进它..下面是我的新代码。

private static BasicPay  getEmployeeForEmpFinance(int empPersionalinfoID)
{

    var context = new SSPModel.sspEntities();
    var query = from c in context.Employee_Financial
                join d in context.Employee_Employ on
                c.Employee_Personal_InfoEmp_id equals d.Employee_Personal_InfoEmp_id
                where c.Employee_Personal_InfoEmp_id == empPersionalinfoID
                select new BasicPay
                {
                    employee_personal_id = c.Employee_Personal_InfoEmp_id,
                    grade_id = d.Grade_Id,
                    base_pay = c.Base_Pay,
                    housing = c.Housing_Allowance
                };
  var y = query.SingleOrDefault();

  return y;
}

public static void employeeEmploy（int payperiodID）{

            var context = new SSPModel.sspEntities();
            var query = from c in context.Payroll_Batch
                        where c.PayperiodID == payperiodID
                        select c.Payroll_GroupID;
            int y = query.SingleOrDefault();

            Debug.WriteLine("group id: " + y);

            var query2 = from i in context.Employee_Employ
                         where (i.Payroll_Group == y && i.Grade_Id != null)
                         select new { i.ID,i.Employee_Personal_InfoEmp_id, i.Date_of_Appointment, i.Date_of_Employment, i.Grade_Id, i.Substantive_designation };
           var  empEmploy = query2.ToList();

           var basics = new List<BasicPay>();

           foreach (var x in empEmploy)
           {
               basics.Add(getEmployeeForEmpFinance(x.Employee_Personal_InfoEmp_id));


           }
           for (int c=0; c < basics.Count(); c++)
           {
               Debug.WriteLine(basics.ElementAt(c).employee_personal_id);
           }

}

在执行此操作时，我在结束时收到以下错误。

对象引用未设置为对象的实例。

描述：执行期间发生了未处理的异常   当前的网络请求。请查看堆栈跟踪了解更多信息   有关错误的信息以及它在代码中的起源。

异常详细信息：System.NullReferenceException：不是对象引用   设置为对象的实例。

注意 - 它确实打印出正确的数据集。最后得到这个错误。任何理由??

Answer 1

您无法将匿名对象插入List 简单地做这样的事情：

 var query = from c in context.Employee_Financial
                        join d in context.Employee_Employ on
                        c.Employee_Personal_InfoEmp_id equals d.Employee_Personal_InfoEmp_id
                        where c.Employee_Personal_InfoEmp_id == empPersionalinfoID
                        select 
         new BasicPay 
         {
                  position_id = blah.ID,
                  housing = blah.Housing

        };
//I'm making stuff up as the property because I don't understand the stuff you are filling.
//Fill as appropriate

之后：

var y = query.SingleOrDefault();
var basics = new List<BasicPay>();
basics.Add(y);

您无法y.ID或y.SomeProperty，因为y是object .. object没有这些属性。所以一些建议的答案是行不通的：（

Answer 2

怎么样

basic.Add(new BasicPay { employee_personal_id = y.Employee_Personal_InfoEmp_id, grade_id = y.Grade_Id});

Answer 3

您正在创建BasicPay列表，因此您应该将此类型的实例放入列表中：

basic.Add(new BasicPay {employee_personal_id = y.Employee_Personal_InfoEmp_id, grade_id = y.Grade_Id});

Answer 4

我想以下解决方案可以帮助您

BasicPay objPay = new BasicPay();
   objPay.employee_personal_id  = y.Employee_Personal_InfoEmp_id;
   objPay.grade_id              = y.Grade_Id;

   basic.Add ( objPay );

）

Answer 5

要么缺少构造函数，要么必须从默认构造函数初始化它：

public BasicPay(int empId, int gradeId)
{
    --> here initialization
}

或者当您将所有属性设置为public时，您可以使用默认构造函数：

basic.Add(new BasicPay
{
   employee_personal_id=y.Employee_Personal_InfoEmp_id,
   grade_id = y.Grade_Id
});

创建自定义链接类

5 个答案: